#include <iostream>
#include <list>

namespace byh
{
    template class <T>
    class queue
    {
    public:
        queue(){}
        //先进
        void push(const T& x)
        {
            _qu.push_back(x);
        }
        //先出
        void pop()
        {
            _qu.pop_front();
        }
        const T& front()
        {
            return _qu.front();
        }
        size_t size()
        {
            return _qu.size();
        }
        bool empty()
        {
            return _qu.empty();
        }
    private:
        std::list<T> _qu;
    };
}


